How to dynamically populate a checkbox field

I have seen a few examples of how to do it for checkboxes on the forums but they all seem to create the checkboxes on the fly using the gform_pre_render hook. My situation seems to be a bit different as I already have the checkbox with all the fields created and all I want to do is to check the boxes based on the values in the database. The data is contained in the post meta and when I use the following code it checks only the first value encountered...

add_filter('gform_field_value_postmeta_community_amenities', create_function("", '$value = populate_postmeta(\'community_amenities\'); return $value;' ));

function populate_postmeta($meta_key){
	$postID = '469';
	$value = get_post_meta($postID, $meta_key, true);
	return $value;
}

Any ideas on what am I doing wrong?

Yes. Basically I have 2 forms, one where I allow the user to check the checkboxes that he needs and upon subimttal it creates a post where all the checkbox data gets saved as a post meta value. Then I have this second form that would allow them to edit their data.

Found a solution

Add the below code to your functions.php file. Make sure to change the form ID 51 to what ever form that has your checkboxes.

http://www.pastie.org/3391927